Ameren Corporation

ITEM 8.01 Other Events. On July 31, 2026, Ameren Corporation (the “Company”) delivered a notice pursuant to Section 3(x) of its Equity Distribution Sales Agreement dated May 12, 2021, as amended and supplemented, including by the First Amendment to Equity Distribution Sales Agreement dated August 7, 2025 (as so amended and supplemented, the “Sales Agreement”), with Barclays Capital Inc., BofA Securities, Inc., Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, Mizuho Securities USA LLC, Morgan Stanley & Co. LLC, MUFG Securities Americas Inc., RBC Capital Markets, LLC and Wells Fargo Securities, LLC, as sales agents and as forward sellers (in such capacities as applicable, the “Agents” and the “Forward Sellers”), and Bank of America, N.A., Barclays Bank PLC, Goldman Sachs & Co. LLC, JPMorgan Chase Bank, National Association, Mizuho Markets Americas LLC, Morgan Stanley & Co. LLC, MUFG Securities EMEA plc, Royal Bank of Canada and Wells Fargo Bank, National Association, as forward purchasers (the “Forward Purchasers”), increasing by $2,000,000,000 the aggregate gross sales price authorized under the Company’s equity distribution program (the “Program”), pursuant to which the Company, through the Agents or the Forward Sellers, may offer and sell from time to time shares of the Company’s common stock, par value $0.01 per share (the “Common Stock”). After giving effect to such increase, Common Stock with an aggregate gross sales price of up to $2,266,700,000 remains available for issuance under the Program. The Company has no obligation to offer or sell any Common Stock under the Sales Agreement and may at any time suspend offers under the Sales Agreement. This Current Report on Form 8-K is also being filed to report Exhibit 5.